Atomic layer deposition of antimony oxide films

ABSTRACT

Antimony oxide thin films are deposited by atomic layer deposition using an antimony reactant and an oxygen source. Antimony reactants may include antimony halides, such as SbCl 3 , antimony alkylamines, and antimony alkoxides, such as Sb(OEt) 3 . The oxygen source may be, for example, ozone. In some embodiments the antimony oxide thin films are deposited in a batch reactor. The antimony oxide thin films may serve, for example, as etch stop layers or sacrificial layers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/649, 992, filed Oct. 11, 2012, which claims priority to U.S.Provisional application No. 61/546,500, filed Oct. 12, 2011 and U.S.Provisional application No. 61/597,373, filed Feb. 10, 2012, thedisclosures of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present application relates to deposition of Sb₂O₃ films by atomiclayer deposition.

SUMMARY OF THE INVENTION

Antimony oxide thin films can be deposited by atomic layer deposition(ALD). In one aspect, antimony oxide thin films are deposited fromalternating and sequential pulses of an antimony source and an oxygensource.

In some embodiments the antimony source comprises an antimony halide, anantimony alkoxide or an antimony alkylamine compound. The oxygen sourcemay be, for example, ozone. In some embodiments the oxygen sourcecomprises plasma. In some embodiments the oxygen source is not water.

In some embodiments antimony oxide thin films are deposited using an ALDcycle comprising alternating and sequential pulses of an antimonyalkoxide and an oxygen source, such as ozone. The antimony alkoxide maybe, for example, Sb(OEt)₃. The films may be deposited in a batch reactoror a single-wafer reactor and may be used, for example, as a sacrificiallayer or as an etch stop layer.

In some embodiments antimony oxide thin films are deposited by an ALDcycle comprising alternating and sequential pulses of an antimonyalkylamine and an oxygen source, such as ozone. The films may bedeposited in a single-wafer reactor or a batch reactor and may be used,for example, as a sacrificial layer or as an etch stop layer.

In some embodiments, pulses of water may be included in the depositionprocess. When water is included, the oxygen source is not water.

In another aspect, antimony oxide thin films are deposited by an ALDprocess comprising alternating and sequential pulses of an antimonyprecursor and water. In some embodiments the antimony precursor is anantimony halide, an antimony alkylamine or an antimony alkoxide.

In some embodiments the antimony halide reactant may be SbCl₃. In someembodiments the antimony alkoxide reactant may be Sb(OEt)₃. In someembodiments the antimony alkylamine reactant may be Sb(N(CH3₂)₂)₃.

In some embodiments the stoichiometry of the antimony oxide deposited byALD may be SbO_(x), where x is from about 1 to about 3. In someembodiments the stoichiometry of the antimony oxide may be Sb₂O₃, Sb₂O₅or mixtures thereof. In some embodiments the stoichiometry of theantimony oxide is Sb₂O₃. In other embodiments the stoichiometry of theantimony oxide is Sb₂O₅. In some embodiments the stoichiometry of theantimony oxide is a mixture of Sb₂O₃ and Sb₂O₅. In other embodiments theantimony oxide has a different stoichiometry.

In some embodiments the ALD process is a thermal ALD process. In someembodiments the ALD process is a plasma enhanced ALD process (PEALD).

In some embodiments the ALD process is carried out in a batch reactor.In some embodiments the ALD process is carried out in a single waferreactor.

In some embodiments the antimony oxide may be doped with anothermaterial, such as a different metal or metal oxide. That is, at leastone metal of the different metal or metal oxide is not antimony. Forexample, the antimony oxide may be doped with aluminum oxide (Al₂O₃).

In some embodiments, antimony oxide films deposited by ALD are used insolid state doping applications, such as in the formation of FinFets.For example, antimony oxide may be deposited on silicon and temperaturecan be used to drive dopant (Sb) into the underlying silicon. A sharpdopant (Sb) profile may be obtained, as the diffusion coefficient ismagnitudes lower than that of P.

In some embodiments a method of doping a material such as a siliconsubstrate comprises depositing antimony oxide by ALD directly over andcontacting the material and anneal to drive the dopant from the antimonyoxide layer into the underlying material.

In some embodiments, antimony oxide thin films deposited by ALD may beused as a p-type cap layer in PMOS. For example, a thin layer ofantimony oxide can be deposited by ALD on a gate dielectric, therebyshifting the threshold voltage toward p-type. In some embodiments aSi/SiO₂/HfO₂/SbO_(x)/TiN structure is formed.

In some embodiments, antimony oxide thin films deposited by ALD can beused as a sacrificial layer (for example deposited on a resist) fordouble or quadruple patterning. A method of multiple patterning maycomprise depositing a conformal antimony oxide layer over a patternedresist layer on a substrate by ALD, etching the antimony oxide layer,removing the resist and etching the substrate. In some embodiments anantimony oxide thin film deposited by ALD is used as an etch stop layer.

In some aspects antimony oxide thin films deposited by ALD can be usedto form structures on a semiconductor substrate. A first layercomprising a first material is deposited on a substrate. A second layerof antimony oxide is deposited on the substrate by ALD. The ALD processmay comprise alternately and sequentially contacting the substrate withan antimony precursor and an oxygen precursor. The first or second layeris subsequently etched. In some embodiments the first layer comprisingthe first material is selectively etched relative to the second antimonyoxide layer. In other embodiments the second antimony oxide layer isselectively etched relative to the first layer. The first layer maycomprise, for example, SiO₂ or Al₂O₃. The ALD process for depositing thesecond antimony oxide film may be carried out in a batch reactor in someembodiments. In some embodiments the second layer comprising antimonyoxide is deposited prior to depositing the first layer comprising afirst material. For example, the second layer may be deposited directlyon the first layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood from the detailed description ofsome of the embodiments and from the appended drawings, which are meantto illustrate and not to limit the invention, and wherein:

FIGS. 1A and B show Sb₂O₃ layers deposited on structured photoresist.

FIG. 2A shows the growth rate of Sb₂O₃ films deposited from Sb(OEt)₃ andO₃ as a function of temperature.

FIG. 2B shows film non-uniformity of Sb₂O₃ films deposited from Sb(OEt)₃and O₃ as a function of temperature, as measured from 21 points using aspectroscopic ellipsometer.

FIG. 2C also shows film non-uniformity of Sb₂O₃ films deposited fromSb(OEt)₃ and O₃ as a function of temperature.

FIG. 3 shows an AFM image of a 25 nm Sb₂O₃ film deposited at 100° C.

FIG. 4A shows the growth rate of Sb₂O₃ films deposited from SbCl₃ and O₃as a function of temperature.

FIG. 4B shows film non-uniformity of Sb₂O₃ films deposited from SbCl₃and O₃ as a function of temperature. Measurements were taken at 21points using a spectroscopic ellipsometer.

FIG. 5 illustrates the growth rate of SbO_(x) as a function ofSb(N(CH₃)₂)₃ pulse time.

FIG. 6 shows the thickness profile (nm) of SbO_(x) deposited at 100° C.from Sb(N(CH₃)₂)₃+O₃.

FIG. 7 illustrates the growth rate of SbO_(x) from Sb(OEt)₃ and O₃ as afunction of the estimated O₃ dosage injected in the reactor.

FIG. 8 is a thickness non-uniformity map of an SbO_(x) film depositedusing the conditions described in Example 6.

DETAILED DESCRIPTION

Antimony oxide films (SbO_(x)) can be deposited by atomic layerdeposition processes using antimony precursors and oxygen sourcereactants. In some embodiments antimony precursors may be antimonyhalides, antimony alkoxides and/or antimony alkylamines. For example, insome embodiments, Sb₂O₃ films can be deposited by ALD using Sb(OC₂H₅)₃and O₃. In some embodiments Sb₂O₃ films are deposited by ALD using SbCl₃and O₃.

Antimony oxide deposited by ALD can be used in a variety of contexts,for example as a p-type capping layer, in solid state dopingapplications as a dopant source for doping underlying silicon and inmultiple patterning applications. The antimony oxide can be used as asacrificial layer as there are differences in etching propertiescompared to SiO₂.

The thickness and composition of the antimony oxide films can becontrolled to produce a film with the desired characteristics. Antimonyoxide is generally referred to herein as SbO_(x). However, the exactstoichiometry can vary. In some embodiments, X can be about 1 to about3, or about 1.2 to about 2.5. In some embodiments the stoichiometry ofthe antimony oxide is Sb₂O₃. In other embodiments the stoichiometry ofthe antimony oxide is Sb₂O₅. In some embodiments the stoichiometry ofthe antimony oxide is a mixture of Sb₂O₃ and Sb₂O₅. In some embodimentsthe antimony oxide has a different stoichiometry.

ALD type processes are based on controlled, self-limiting surfacereactions of precursor chemicals. Gas phase reactions are avoided bycontacting the substrate alternately and sequentially with theprecursors. Vapor phase reactants are separated from each other in thereaction chamber, for example, by removing excess reactants and/orreactant byproducts from the reaction chamber between reactant pulses.

The methods presented herein allow deposition of antimony oxide films onsubstrate surfaces. Geometrically challenging applications are alsopossible due to the nature of the ALD-type processes and the ability todeposit conformal thin films. According to some embodiments, atomiclayer deposition (ALD) type processes are used to form antimony oxidefilms on substrates such as integrated circuit workpieces.

A substrate or workpiece is placed in a reaction chamber and subjectedto alternately repeated surface reactions. In particular, in someembodiments thin films are formed by repetition of a self-limiting ALDcycle. Preferably, each ALD cycle comprises at least two distinctphases. In a first phase, one reactant will form no more than about onemonolayer on the substrate surface. This reactant includes antimony.This reactant, also referred to herein as “the antimony reactant” or“antimony precursor” may be, for example, an antimony halide, antimonyalkoxide or antimony alkylamide. A second reactant comprising oxygen(the “oxygen source”) is provided and reacts with the adsorbed antimonyprecursor to form an antimony oxide. The oxygen source may compriseplasma in some embodiments. Exemplary oxygen sources include water,ozone and oxygen plasma. A third reactant may be included in someembodiments, for example to enhance the growth of the antimony oxide. Insome embodiments, the third reactant may be water. Although referred toas the first and second phases and the first, second and third reactant,an ALD cycle may begin with any one of the reactants.

In some embodiments the substrate on which deposition is desired,preferably a semiconductor workpiece, is loaded into a reactor. Thereactor may be part of a cluster tool in which a variety of differentprocesses in the formation of an integrated circuit are carried out. Insome embodiments a flow-type reactor is utilized. In some embodiments ahigh-volume manufacturing capable single wafer ALD reactor is used.

In other embodiments a batch reactor comprising multiple substrates isused. For some embodiments in batch ALD reactors, the number ofsubstrates is preferably in the range of 10 to 200, more preferably inthe range of 50 to 150, and most preferably in the range of 100 to 130.In some embodiments a batch reactor is used with more than 50 wafers,more than 100 wafers or more than 150 wafers. In some embodiments avertical batch reactor is utilized in which the boat rotates duringprocessing, such as the A412™ reactor from ASM Europe B. V. (Almere,Netherlands). Thus, in some embodiments the wafers rotate duringprocessing.

Exemplary single wafer reactors, designed specifically to enhance ALDprocesses, are commercially available from ASM America, Inc. (Phoenix,Ariz.) under the tradenames Pulsar® 2000 and Pulsar® 3000. Exemplarybatch ALD reactors, designed specifically to enhance ALD processes, arecommercially available from and ASM Europe B.V (Almere, Netherlands)under the tradenames A4ALD™ and A412™. In some embodiments an F-450™ ALDreactor supplied by ASM Microchemistry Oy, Espoo is used. Other reactorsthat can be used or modified to be used will be apparent to the skilledartisan.

In some embodiments the substrate is a 300 mm wafer. In otherembodiments the substrate is a 450 mm wafer. These large wafers may beused in single wafer reactors or in batch reactors.

In some embodiments the maximum with-in-wafer thickness non-uniformitiesfor the antimony oxide films deposited by ALD are less than about 15%(1σ), less than about 10%, less than about 5% or less than about 3%. Insome embodiments in which a batch reactor is used, wafer-to-waferuniformity is less than 3% (1σ), less than 2%, less than 1% or even lessthan 0.5%.

As mentioned briefly above, the ALD processes disclosed herein alsoallow for conformal deposition on three-dimensional structures. In someembodiments step coverage of a deposited SbO_(x) film on athree-dimensional structure is greater than 50%, greater than 80%,greater than 90% or even greater than 95%.

In some embodiments, if necessary, the exposed surfaces of the workpiececan be terminated to react with the first phase of the ALD process. Insome embodiments a separate termination step is not required.

As discussed in more detail below, in some embodiments, one or moreSbO_(x) deposition cycles begin with provision of the antimonyprecursor, followed by the oxygen source. In other embodimentsdeposition may begin with provision of the oxygen source, followed bythe antimony precursor. The reaction chamber is typically purged betweenreaction pulses. The cycle is repeated until a film of the desiredthickness is obtained. In some embodiments, one or more cycles withinthe ALD process are varied to obtain a film with a desired composition.

In some embodiments, the antimony precursor is provided first. After theinitial surface termination, if necessary or desired, a first antimonyprecursor pulse is supplied to the workpiece. In accordance with someembodiments, the first reactant pulse comprises a carrier gas flow and avolatile antimony species, such as SbCl₃ or Sb(OEt)₃, that is reactivewith the workpiece surfaces of interest. Accordingly, the antimonyreactant adsorbs upon the workpiece surfaces. The first reactant pulseself-saturates the workpiece surfaces such that any excess constituentsof the first reactant pulse do not further react with the molecularlayer formed by this process.

The first antimony reactant pulse is preferably supplied in gaseousform. The antimony reactant gas is considered “volatile” for purposes ofthe present description if the species exhibits sufficient vaporpressure under the process conditions to transport the species to theworkpiece in sufficient concentration to saturate exposed surfaces.

The antimony reactant is pulsed for a time period sufficient to saturatethe substrate surface to a desired extent.

After sufficient time for a molecular layer to adsorb on the substratesurface, excess first reactant is then removed (purged) from thereaction space. In some embodiments the flow of the first reactant isstopped while continuing to flow a carrier gas or purge gas for asufficient time to diffuse or purge excess reactants and reactantby-products, if any, from the reaction space. Provision and removal ofthe antimony reactant can be referred to as the antimony phase of theALD cycle.

An oxygen source (second reactant) is pulsed into the reaction space tocontact the substrate surface and react with the adsorbed antimonyprecursor to form an antimony oxide layer. The oxygen source maycomprise, for example, ozone, water or oxygen radicals. Oxygen sourceconcentration and pulsing time can also be determined based on theparticular circumstances. In some embodiments, the oxygen sourceconcentration may be about 10 to about 400 g/m³ (NTP), or from about 60to about 300 g/m³. The flow rate of the oxygen source into the chambermay be, for example, from about 100 to about 1000 cm³/min (NTP), or fromabout 200 to 800 cm³/min.

After a time period sufficient to completely saturate and react themolecular layer with the oxygen pulse, any excess second, oxygenreactant is removed from the reaction space. As with the removal of thefirst reactant, this step may comprise flowing a purge gas for a timeperiod sufficient for excess reactive species and volatile reactionby-products to be purged from the reaction space. Together, the oxygenreactant provision and removal represent a second phase in process, andcan also be considered the oxygen phase.

The antimony phase and the oxygen phase together represent one ALDcycle, which is repeated to form antimony oxide thin films of thedesired thickness. Although the oxygen phase may also be described as an‘oxidation’ phase, one skilled in the art will understand that oxidationreactions, i.e. oxidation state changes, are not necessarily takingplace. Unless otherwise indicated, the term oxidation phase is used torefer to the phase where the oxygen source is provided and removedto/from the reaction space.

As discussed below, in some embodiments a third phase by be included, inwhich water (or another reactant) is pulsed to the substrate. A vaporphase pulse of water is provided to the reaction space, allowed toreact, and then removed from the reaction space, such as by purging withan inert gas. In some embodiments the water phase is provided after theantimony phase and prior to the oxidation phase. In other embodimentsthe water phase is provided after the oxidation phase and subsequent tothe next antimony phase. When water is used, the oxidation phaseutilizes an oxygen source other than water.

The exact pulsing times for the antimony reactant and oxygen source canbe determined based on the particular circumstances. In some embodimentsthe pulse time for the antimony reactant and/or the oxygen source isabout 0.05 to 180 seconds, 0.1 to 50 seconds, 1 to 10 seconds or about 2seconds. Depending on the reactor type, substrate type and its surfacearea, the pulsing time for the antimony reactant and oxygen precursormay be even higher than 180 seconds. In some embodiments, pulsing timescan be on the order of minutes. The optimum pulsing time can be readilydetermined by the skilled artisan based on the particular circumstances.

Typical purging times are from about 0.05 to 20 seconds, for examplebetween about 1 and 10, or even between about 1 and 2 seconds. However,other purge times can be utilized if necessary, such as when depositinglayers over extremely high aspect ratio structures or other structureswith complex surface morphology is needed.

In some embodiments using a batch reactor, antimony reactant pulse timesare about 1 to about 60 seconds, the antimony reactant is purged forabout 5 to about 600 seconds, the oxygen source is pulsed for about 1 toabout 60 seconds and the oxygen source is removed by purging for about 5to about 600 seconds.

While the ALD cycle is generally referred to herein as beginning withthe antimony phase, it is contemplated that in other embodiments thecycle may begin with the oxygen phase. One of skill in the art willrecognize that the first reactant phase generally reacts with thetermination left by the last phase in the previous cycle, if any. Thus,while no reactant may be previously adsorbed on the substrate surface orpresent in the reaction space if the oxygen phase is the first phase inthe first ALD cycle, in subsequent cycles the oxygen phase willeffectively follow the antimony phase.

In some embodiments, an antimony phase comprises providing a pulse of anantimony halide, such as SbCl₃, an antimony alkylamine or an antimonyalkoxide, such as Sb(OEt)₃. Excess antimony precursor is removed and theprecursor is contacted with a pulse of an oxygen source, such as ozoneor water to form a layer of antimony oxide.

As mentioned above, each pulse or phase of each ALD cycle is typicallyself-limiting. An excess of reactants is supplied in each phase tosaturate the susceptible structure surfaces. Surface saturation ensuresreactant occupation of all available reactive sites (subject, forexample, to physical size or “steric hindrance” restraints) and thusensures excellent step coverage. However, in some embodiments thereaction conditions may be manipulated such that one or more of thephases is not self-limiting.

According to one embodiment, an antimony oxide thin film is formed on asubstrate by an ALD type process comprising multiple antimony oxidedeposition cycles, each deposition cycle comprising:

contacting a substrate with a vaporized antimony compound such that theantimony compound adsorbs to the substrate;

Removing excess antimony compound and reaction byproducts, if any;

contacting the substrate with an oxygen source, thereby converting theadsorbed antimony compound into antimony oxide; and

removing excess unreacted oxygen source and reaction byproducts.

The contacting and removing steps are repeated until a thin film of adesired thickness and composition is obtained.

As discussed above, the deposition process typically comprises multipleALD deposition cycles. In some embodiments, the antimony oxide may bedoped, for example with a metal or metal oxide, such as aluminum oxide.Thus, in some embodiments antimony oxide deposition cycles may beprovided at a desired ratio with metal or metal oxide deposition cycles.The ratio of antimony oxide deposition cycles to metal or metal oxidedeposition cycles may be selected to control the dopant concentration inthe ultimate antimony oxide film deposited by the ALD process. Forexample, for a low dopant density, the ratio of antimony oxide cycles tometal or other metal oxide deposition cycles may be on the order of10:1. For a higher concentration of dopant, the ratio may range up toabout 1:1 or greater.

In addition, the density of a dopant can be varied across the thicknessof the film by changing the ratio of antimony oxide cycles to dopantdeposition cycles during the deposition process.

Deposition temperatures are maintained below the thermal decompositiontemperature of the reactants but at a high enough level to avoidcondensation of reactants and to provide the activation energy for thedesired surface reactions. Of course, the appropriate temperature windowfor any given ALD reaction will depend upon the surface termination andreactant species involved. Here, the temperature is preferably at orbelow about 500° C. In some embodiments the deposition temperature isabout 50 to about 400° C. For SbCl₃, the deposition temperature ispreferably at or above about 35° C., for example about 35° C. to about500° C. For Sb(OEt)₃, the deposition temperature is preferably at orabove about room temperature, for example about room temperature toabout 500° C.

In some embodiments in which a batch reactor is used the depositiontemperature is between about 20° C. and about 500° C., between about100° C. and about 400° C., between about 120° C. and about 300° C. orbetween about 150° C. and about 250° C.

The deposition processes can be carried out at a wide range of pressureconditions, but it is preferred to operate the processes at reducedpressure. The pressure in the reaction chamber is typically from about0.01 to about 500 mbar or more. However, in some cases the pressure willbe higher or lower than this range, as can be readily determined by theskilled artisan. In some embodiments the pressure in a single waferreactor is maintained between about 0.01 mbar and 50 mbar, or betweenabout 0.1 mbar and 10 mbar. In some embodiments the pressure in a batchALD reactor is maintained between about 1 mTorr and 500 mTorr, orbetween about 30 mTorr and 200 mTorr.

The antimony source temperature is preferably set below the depositionor substrate temperature. This is based on the fact that if the partialpressure of the source chemical vapor exceeds the condensation limit atthe substrate temperature, controlled layer-by-layer growth of the thinfilm is compromised. For example, for SbCl₃ the source temperature isabout 35° C. in some embodiments while for Sb(OEt)₃ the sourcetemperature is about room temperature in some embodiments.

In some embodiments, the deposited antimony oxide thin films have stepcoverage of greater than about 80%, greater than about 90%, greater thanabout 95% or step coverage of about 100%.

In general, the source materials, (e.g., antimony source materials), arepreferably selected to provide sufficient vapor pressure, sufficientthermal stability at substrate temperature, and sufficient reactivity ofthe compounds for effecting deposition by ALD. “Sufficient vaporpressure” typically supplies enough source chemical molecules in the gasphase to the substrate surface to enable self-saturated reactions at thesurface at the desired rate. “Sufficient thermal stability” typicallymeans that the source chemical itself does not form growth-disturbingcondensable phases on the surface or leave harmful level of impuritieson the substrate surface through thermal decomposition. In other words,temperatures are kept above the condensation limits and below thethermal decomposition limits of the selected reactant vapors. One aim isto avoid uncontrolled condensation of molecules on the substrate.“Sufficient reactivity” typically results in self-saturation in pulsesshort enough to allow for a commercially acceptable throughput time.Further selection criteria include the availability of the chemical athigh purity and the ease of handling of the chemical.

In some embodiments the antimony reactant comprises an antimony halide.For example, the antimony halide may be SbCl₃. In other embodiments theantimony halide may be SbBr₃, SbF₃ or SbI₃. In some embodiments theantimony halide comprises at least one halide ligand. In someembodiments the antimony halide is SbX_(z)A_(3-z), wherein z is from 1to 3 and A is a ligand comprising alkylamine, a halide different from X,or an amine, silyl, alkoxide or alkyl group.

In some embodiments the antimony reactant comprises an antimonyalkoxide. For example, the antimony reactant may comprise Sb(OEt)₃. Insome embodiments the antimony reactant may comprise Sb(OR)₃, whereineach R can be independently selected to be a linear, branched, orcyclic, saturated or unsaturated, C1-C12 alkyl or alkenyl group. Thealkyl or alkenyl might also be substituted with substituents such ashalogens, amines, silyls etc. In some embodiments the antimony reactantmay comprise Sb(OR)_(x)A_(3-x), wherein x is from 1 to 3, each R can beindependently selected to be a linear or branched, cyclic or linear,saturated or unsaturated, C1-C12 alkyl or alkenyl group. The alkyl oralkenyl might also be substituted with substituents like halogens,amines, silyls. A is ligand comprising alkylamine, halide, amine, silylor alkyl.

While antimony oxide can be deposited using antimony halides or antimonyalkoxides as antimony sources, as described above, in some embodimentsother types of antimony sources can be used, such as antimonyalkylamines and antimony alkyls. For example, alternative antimonysources can be used in specific applications, such as deposition ofantimony oxide films to serve as sacrificial layers. The sacrificiallayers may be used, for example, in double or quadruple patterning.

In some embodiments antimony alkylamines are used. The antimony reactantmay comprise, for example, Sb(NR₂)_(x)A_(3-x), wherein x is from 1 to 3,and each R can be independently selected to be linear, branched orcyclic, saturated or unsaturated, C1-C12 alkyl or alkenyl group orhydrogen if the other R is not hydrogen. In some embodiments the alkylor alkenyl might also be substituted with substituents such as halogens,amines, silyls etc. . . . . A can be a ligand comprising alkylamine,halide, amine, silyl or alkyl. A specific example of this kind precursoris tris(dimethylamine)antimony, Sb(NMe₂)₃. Other non-limiting examplesare C2-C3 variants: Sb(NEt₂)₃, Sb(NPr₂)₃ and Sb(N^(i)Pr₂)₃. The R inSb(NR₂)₃ can be linear or branched, cyclic or linear, saturated orunsaturated, C1-C12 alkyl or alkenyl group. The alkyl or alkenyl mightalso be substituted with substituents like halogens, amines, silyls etc.

Another type of antimony compounds that can be used are antimony alkylshaving the formula SbR_(x)A_(3-x), wherein x is from 1 to 3, each R canbe independently selected to be a linear, branched, or cyclic, saturatedor unsaturated, C1-C12 alkyl or alkenyl group. In some embodiments thealkyl or alkenyl can also be substituted with substituents likehalogens, amines, silyls etc A is a ligand comprising alkylamine,halide, amine, silyl or alkyl.

While in some of the above-mentioned antimony compounds the oxidationstate of antimony is +III, similar antimony compounds, such asalkoxides, halides, alkyls and alkylamines or mixtures or derivativesthereof, can be use that have different antimony oxidation states, like+V.

In some embodiments the oxygen source material is selected from thegroup consisting of water, oxygen, hydrogen peroxide, aqueous solutionof hydrogen peroxide, ozone, atomic oxygen, oxides of nitrogen, peracids(—O—O—H), alcohols, oxygen-containing radicals and mixtures thereof.Other oxygen sources can also be employed, such as remotely or in situgenerated oxygen plasma.

The oxygen source may be an oxygen-containing gas pulse and can be amixture of oxygen and inactive gas, such as nitrogen or argon. In someembodiments the oxygen source may be a molecular oxygen-containing gaspulse. In some embodiments the oxygen content of the oxygen-source gasis from about 10 to 25%. Thus, one source of oxygen may be air. In someembodiments, the oxygen source is molecular oxygen. In some embodiments,the oxygen source comprises an activated or excited oxygen species.

In some embodiments, the oxygen source comprises ozone. The oxygensource may be pure ozone or a mixture of ozone, molecular oxygen, andanother gas, for example an inactive gas such as nitrogen or argon.Ozone can be produced by an ozone generator and it is most preferablyintroduced into the reaction space with the aid of an inert gas of somekind, such as nitrogen, or with the aid of oxygen. In some embodiments,ozone is provided at a concentration from about 5 vol- % to about 40vol- %, and preferably from about 15 vol- % to about 25 vol- %. In otherembodiments, ozone is formed inside the reactor, for example byconducting oxygen containing gas through an arc.

In other embodiments, an oxygen containing plasma is formed in thereactor. In some embodiments, the plasma may be formed in situ on top ofthe substrate or in close proximity to the substrate. In otherembodiments, the plasma is formed upstream of the reaction chamber in aremote plasma generator and plasma products are directed to the reactionchamber to contact the substrate. As will be appreciated by the skilledartisan, in the case of remote plasma, the pathway to the substrate canbe optimized to maximize electrically neutral species and minimize ionsurvival before reaching the substrate.

In some embodiments water is not used as the oxygen source. In someembodiments water is used as an oxygen source. In other embodiments,water is used in combination with one or more additional oxygen sources.The water may be provided with the additional oxygen source orseparately. In some embodiments a water pulse is provided prior to apulse of a second oxygen source, such as ozone. In other embodiments, awater pulse is provided subsequent to a pulse of a second oxygen source,such as ozone. The reaction chamber may be purged between each pulse.

As mentioned above, in some embodiments, the antimony oxide film can beused as a dopant source for an underlying layer, such as for doping asemiconductor. For example, an antimony oxide can be deposited overanother layer, such as a silicon layer, by an ALD process as disclosedherein and annealing can be carried out to drive dopant (Sb) into theunderlying silicon layer. The semiconductor layer to be doped may be,for example, a fin of a finFET device.

In some embodiments an antimony oxide layer is deposited over a siliconsubstrate and annealed to drive dopant (Sb) into the silicon substrate.

In some embodiments, an antimony oxide layer can be used as a surfacepassivation film for c-Si based solar cells.

In some embodiments, an antimony oxide layer can serve as a p-typecapping layer in PMOS. For example, a thin antimony oxide layer can bedeposited on top of a gate dielectric. The antimony oxide layer may thusserve to shift the threshold voltage towards p-type. In some embodimentsa multi-layer structure is deposited comprisingSi/SiO₂/HfO₂/SbO_(x)/TiN, where at least the SbO_(x) layer is depositedby ALD, as described herein.

In some embodiments, the antimony oxide thin films can be used inmultiple patterning applications (such as double exposure, doubledevelopment, spacer defined double patterning, triple and quadrupleexposure etc. . . . ). The antimony oxide thin films may serve, forexample as sacrificial layers or etch stop layers.

In part because of a delay in introduction of extreme ultravioletlithography (EUV), double patterning is used to decrease the criticaldimension (CD). One approach that is used is called spacer defineddouble patterning (SDDP). Briefly, a uniform, conformal layer isdeposited on a patterned core (also called a mandrel or template) thatcan be, for example, amorphous carbon. After dry etch, spacers arecreated which act as a template/mask to form patterns in the lowerlayer(s). The spacer material layer thickness determines the CD and CDuniformity. A good within wafer uniformity is desired (3 SIGMA of 10% ofthe CD value is a good reference). In some embodiments, an antimonyoxide layer is deposited by ALD as described herein as part of an SDDPprocess. The antimony oxide layer may serve, for example, as theconformal layer used to form the spacers.

In direct SDDP, the spacer is a conformal layer deposited directly onresist. Thus, a low-temperature process (such as below 150° C.) is used.The actual maximum temperature will vary depending on the type ofresist. An advantage of direct SDDP is a decrease in the number ofprocess steps compared to conventional SDDP. A challenge is finding aresist compatible deposition process. In some embodiments, the processdescribed herein are operated at temperatures of less than 150° C., orless than the maximum temperature for a given resist, and thus can beused in this context. In some embodiments an SDDP process, or otherprocess for forming structures on a semiconductor substrate, comprisesdepositing a conformal antimony oxide film by ALD as described hereinand subsequently etching the antimony oxide film. In some embodiments adifferent film on the substrate is etched relative to the antimony oxidefilm.

Additionally, if the spacer has high etch selectivity relative to thetemplate and underlying dielectric, and good mechanical properties(avoiding pattern collapse), a low aspect ratio resist can be used, thusfacilitating lithography and integration. Currently, SiO₂ and SiN areused for forming spacer layers, but these have a challenging etchselectivity toward the template and/or underlying dielectric and thusrequire a high aspect ratio resist. In some embodiments SbO_(x) films,such as Sb₂O₃ films, deposited by the disclosed methods have a moredesirable etch selectivity and are used to form spacer layers. Forexample, experiments have shown that 1% HF, 25% H₂SO₄, conc. HNO₃, and2M NaOH do not etch SbO_(x), whereas it can be removed quickly with concHCl (see Examples below). Compared to traditional SDDP approaches, thismakes higher selectivity towards template and underlying materialpossible.

Because the SbO_(x) deposition processes disclosed herein can, in someembodiments, be carried out at relatively low temperatures, for examplebelow 150° C. or below 100° C., and can be used to form conformal filmswith uniform properties, in some embodiments they can be used for directSDDP. Additionally, because the deposited films can have good mechanicalproperties and good etch selectivity, a low aspect ratio resist can beformed, thereby facilitating lithography and integration.

In some such embodiments, an antimony oxide layer is depositedconformally over a patterned resist by ALD. An example is illustrated inFIG. 1, where an Sb₂O₃ layer was deposited at 100° C. on structuredphotoresist.

The antimony oxide can be used as a sacrificial layer or etch stoplayer. As mentioned above, there are differences in etching propertiesbetween SbO_(x) films and SiO₂ and other materials such as Al₂O₃deposited by ALD. For example, an Sb₂O₃ film deposited from Sb(OEt)₃ andO₃ could not be etched with 1% HF, 25% H₂SO₄, conc. HNO₃ or 2M NaOH.However, the film could be etched in conc. HCl at a rate of about 10nm/min. Thus, in some embodiments Sb₂O₃ film deposited from Sb(OEt)₃ andO₃ can be selectively etched using HCl, or a different film can beselectively etched relative to the Sb₂O₃ film using 1% HF, 25% H₂SO₄,concentrated HNO₃ or 2M NaOH.

On the other hand, an Sb₂O₃ film deposited from SbCl₃ and O₃ could notbe etched with 1% HF, 25% H₂SO₄, conc. HCl, or conc. HNO₃. Thus, in someembodiments a film that can be etched using one or more of thesecompounds can be selectively etched relative to the Sb₂O₃ film depositedfrom these precursors.

In addition it was found that while thermal SiO₂ etched with a rate ofabout 2.8 nm/min in HF solution, an SbO_(x) film deposited as describedherein did not show any notable etching in the same HF solution. Thus,in some embodiments HF is used to selectively etch SiO₂ relative to suchSbO_(x) films. On the other hand, SbO_(x) films could be etched withH₂O₂ at a rate of about 1 to 2 nm/min, thermal SiO₂ does not etch withH₂O₂. Thus, in other embodiments such SbO_(x) films can be selectivelyetched relative to themal SiO₂ using H₂O₂.

SbO_(x) films also have good etch selectivity against Al₂O₃ films, suchas Al₂O₃ films deposited by ALD. H₃PO₄, HF, KOH and TMAH were found toetch Al₂O₃ films deposited by ALD, but did not etch SbO_(x), while Al₂O₃was not etched by H₂O₂, tartaric acid or conc. HCl. Thus, SbO_(x) can beselectively etched relative to Al₂O₃ using H₂O₂, tartaric acid or conc.HCl while Al₂O₃ can be selectively etched relative to SbO_(x) usingH₃PO₄, HF, KOH or TMAH.

In some embodiments, after being deposited over a patterned resistlayer, an antimony oxide layer is etched to expose the underlyingresist. The resist is then removed and the underlying substrate etchedto form the desired features.

Generally the higher the deposition temperature is for SbO_(x) films thehigher etch resistance they have, provided that the deposition is notout of the deposition window i.e. high enough temperature to get goodquality, but low enough to prevent major decomposition of precursor(s)and thus preventing bad quality of the film, for example, impurities duedecomposition.

In some embodiments SbO_(x) films can selectively be etched relative toSiO₂ and Si films or layers. Etching may be performed in gas phase or inliquid phase as a “wet etch”. Exemplary selective etch solutions, inwhich the etching can be performed selectively, include concentratedHCl, H₂O₂ and tartaric acid. Selectivity is preferably over 75% (etchrate difference of 1:3), over 80% (etch rate difference of 1:5), over90% (etch rate difference of 1:10), and in some cases the selectivitycan be over 95% (etch rate difference of 1:20) or even over 98% (etchrate difference 1:50). In some embodiments the etch rate difference canbe 1:100 (selectivity of 99%) or even more.

In some embodiments SiO₂ films can selectively be etched relative toSbO_(x) films or layers deposited as described herein. Etching may beperformed in gas phase or in liquid phase as a “wet etch”. Exemplaryetch solutions, in which the etching can be performed selectivelyinclude HF containing solutions, such as 0.5% or 1.0% diluted HF.Selectivity may be over 75% (etch rate difference of 1:3), over 80%(etch rate difference of 1:5), over 90% (etch rate difference of 1:10),and in some cases over 95% (etch rate difference of 1:20) or even over98% (etch rate difference of 1:50). In some embodiments a selectivity of99% or even higher can be obtained (such as an etch rate difference of1:100).

In some embodiments SbO_(x) films can be selectively etched relative toAl₂O₃ films or layers. Etching may be performed in gas phase or inliquid phase as a “wet etch”. Exemplary selective etch solutions includeconcentrated HCl, H₂O₂ and tartaric acid. Selectivity may be over 75%(etch rate difference of 1:3), over 80% (etch rate difference of 1:5),over 90% (etch rate difference of 1:10), or even over 95% (etch ratedifference of 1:20) or 98% (etch rate difference of 1:50). In some casesthe selectivity can be 99% or more, with an etch rate difference of1:100 or greater.

In some embodiments Al₂O₃ films can selectively be etched relative toSbO_(x) films or layers that have been deposited as described herein.Etching may be performed in gas phase or in liquid phase as a “wetetch”. Exemplary selective etch solutions include H₃PO₄, HF, KOH andTMAH. Selectivity imay be over 75% (etch rate difference of 1:3), over80% (etch rate difference of 1:5), over 90% (etch rate difference of1:10), and in some cases over 95% (etch rate difference of 1:20) or over98% (etch rate difference of 1:50). In some cases a selectivity of 99%or more can be achieved, with an etch rate difference of 1:100 orgreater.

In some embodiments silicon or silicon nitride is etched selectivelyrelative to the SbO_(x) films deposited by ALD as described herein. Inthese cases silicon or silicon nitride can be etched relative to SbO_(x)using common silicon or silicon nitride etchants. SbO_(x) can also beetched selectively relative to silicon or silicon nitride. For example,concentrated HCl, H₂O₂ or tartaric acid can be used. In some embodimentsselectivity is over 75% (etch rate difference of 1:3), over 80% (etchrate difference of 1:5), over 90% (etch rate difference of 1:10), andeven over 95% (etch rate difference of 1:20) or over 98% (etch ratedifference of 1:50). In some cases a selectivity of 99% or more isachieved, with an etch rate difference of 1:100 or even more.

In some embodiments the SbO_(x) films have etch selectivity against adifferent material or vice-versa—the other material can be etchedselectively over SbO_(x). In these cases other material can be etchedselectively relative to SbO_(x) using common known etchants. AlsoSbO_(x) can also be etched selectively relative to the other materialusing concentrated HCl, H₂O₂ or tartaric acid. Selectivity may be over75% (etch rate difference of 1:3), over 80% (etch rate difference of1:5), over 90% (etch rate difference of 1:10), and in some cases over95% (etch rate difference of 1:20) or over 98% (etch rate difference of1:50). In some cases the selectivity can be 99% or more, with an etchrate difference of 1:100 or greater.

In some embodiments the SbO_(x) films can be etched selectively overother materials such as SiN or SiO₂, using dry-etchants. For example, Cland/or F-containing plasma etchants can be used. In some embodimentsCl₂-plasma or a mixture CHF₃ and Cl₂-plasma is used. Again, selectivitymay be over 50% (etch rate difference of 1:2), over 75% (etch ratedifference of 1:3), or even over 90% (etch rate difference of 1:10.

In some embodiments methods of forming a structure on a substrate, suchas in multiple patterning processes, comprise depositing a first filmcomprising a first material and depositing a second film comprisingantimony oxide. Although referred to as the first and second films, thefirst film may be deposited prior to the second film, or the second filmmay be deposited prior to the first film. In some embodiments the secondfilm is deposited directly on the first film, while in other embodimentsthe first film is deposited directly on the second film. The antimonyoxide film is deposited by an ALD process as described herein, forexample by alternately and sequentially contacting the substrate with anantimony reactant, such as an antimony halide, antimony alkoxide orantimony alkylamine, and an oxygen source, such as ozone. The first filmmay then be selectively etched relative to the antimony oxide, or theantimony oxide may be selectively etched relative to the first film. Insome embodiments the first material may be, for example, SiO₂ or Al₂O₃.When the second layer of antimony oxide is etched relative to the firstlayer, etching may comprise contacting the antimony oxide layer with anetchant selected from the group consisting of concentrated HCl, H₂O₂ andtartaric acid. When the first material is etched relative to theantimony oxide layer, etching may comprise contacting the first materialwith an etchant selected from the group consisting of HF, H₃PO₄, KOH andTMAH.

In some embodiments antimony oxide thin films are deposited using an ALDcycle comprising alternating and sequential pulses of an antimonyalkoxide and an oxygen source, such as ozone. The antimony alkoxide maybe, for example, Sb(OEt)₃. The films may be deposited in a batch reactorand may be used, for example, as a sacrificial layer or as an etch stoplayer.

In some embodiments antimony oxide thin films are deposited by an ALDcycle comprising alternating and sequential pulses of an antimonyalkylamine and an oxygen source, such as ozone. The films may bedeposited in a batch reactor and may be used, for example, as asacrificial layer or as an etch stop layer.

EXAMPLES Example 1 Sb(OEt)₃ as the Antimony Source in a Single WaferReactor

Antimony oxide (Sb₂O₃) thin films were deposited by Atomic layerdeposition (ALD) in an F-450 ALCVD™ reactor using Sb(OC₂H₅)₃ as theantimony source and O₃ as the oxygen source.

No film was obtained using Sb(OC2H5)3 (pulse 3.0 s, purge 5.0 s) and H₂O(pulse 1.5 s, purge 5.0 s) at 300° C., but some film was obtained at400° C. (growth rate ˜0.02 Å/cycle).

Films were deposited using alternate and sequential pulses of Sb(OC₂H₅)₃and O₃ at 100-350° C. Sb(OEt)₃ was pulsed for 3.0 s and purged for 5.0s. O₃ was also pulsed for 3.0 s and purged for 5.0 s. The Sb(OC₂H₅)₃ wasused at room temperature (21° C.).

The growth rate ranged from about 0.4 to 1.3 Å/cycle. The growth ratewas 0.4-0.6 Å/cycle at 100-250° C., and >0.8 Å/cycle at 275-350° C. Thefilm non-uniformity was high (>10% 1σ) at 100-150 and −350° C. At200-300° C. the 1σ non-uniformity was <6% and at 275° C. being thelowest about 3%. FIGS. 2A-C show film growth rate and non-uniformity at100-350° C.

The films were characterized with X-ray reflection (XRR), X-raydiffraction (XRD) and X-ray photoelectron spectroscopy (XPS), energydispersive x-ray analysis (EDX) and atomic force microscopy (AFM).According to XRR, the film density was ˜6-6.5 g/cm³ density increasingtowards higher temperature (200-300° C.). The rms roughness obtainedfrom XRR was about 1.4 nm (24-40 nm at 200-300° C.). A very weak peakthat could be addressed to Sb₂O₃ was seen in the XRD diffractogram of asample deposited at 150° C. AFM rms roughness was about 0.31 nm (˜25 nmfilm deposited at 100° C.). The film was smooth and uniform, no contrastwas seen in phase images (FIG. 3).

According to XPS (Table 1), the oxidation state of antimony is +3; thusthe films were Sb₂O₃. Carbon and nitrogen were detected as contaminationon the surface, but after sputtering ˜5 nm neither could be detected.The oxygen concentrations were approximated due to overlap of O1 s andSb3d5 peaks. The decrease in O/Sb (Table 2) is believed to be due topreferential sputtering of the low mass oxygen relative to the high massSb. The XPS samples were deposited at 250° C. EDX detected carbon but nochlorine in a film deposited at 300° C.

Etching tests were done in 1% HF, 25% H₂SO₄, 2M NaOH, conc. HNO₃ andconc. HCl at room temperature. The film could be etched only with conc.HCl (etching rate ˜10 nm/min). Additional etching tests were carried outusing 1% HF, 37% HCl and 0.5M tartaric acid. Results are shown in Table2 below.

TABLE 1 XPS results. Sb₂O₃ film deposited at 250° C. The figures presentat. %. Measured before (top) and after (below) sputtering ~5 nm. C N SbO O/Sb Sample B 14.8 2.5 55 28.2 1.9 Sample B −5 nm 0 — 42 57.6 0.7

As illustrated in FIG. 1, a Sb₂O₃ layer was deposited at 100° C. onstructured photoresist. A thickness target of 30 nm was chosen and thedeposition process comprised 750 cycles. In each cycle, Sb(OEt)₃ waspulsed for 3.5 s and purged for 5.0 s and O3 was pulsed for 3.0 s andpurged for 5 s. Observed step coverage was greater than 95%. A k valueof about 16 was observed.

TABLE 2 Etch results of Sb₂O₃ films deposited by using Sb(OEt)₃ and O₃as reactants and reaction temperatures from about 100 to about 200° C.Solution Temperature (etch solution) etches Sb₂O₃ ? 1% HF RT no 37% HClRT yes 0.5M tartaric acid 50° C. yes

Example 2 SbCl₃ as the Antimony Source in a Single Wafer Reactor

Antimony oxide (Sb₂O₃) thin films were deposited by Atomic layerdeposition (ALD) in an F-450 ALCVD™ reactor using SbCl₃ as the antimonysource and O₃ as the oxygen source. No film was obtained using H₂O asthe oxygen source (SbCl3 pulse 2.0 s, purge 5.0 s; H₂O pulse 1.5 s,purge 5 s). However, the growth can be enhanced and uniformity increasedby using H₂O in addition to O₃. A deposition cycle consisted of a SbCl3pulse 2.0 s, purge 5 s; O3 pulse 3.0 s, purge 5 s; H₂O pulse 1.5 s,purge 5.0 s.

In each ALD cycle, SbCl3 was pulsed for 2 seconds and purged for 5seconds, while ozone was pulsed for 3 seconds and purged for 5 seconds.

Films were deposited at 150-400° C. The evaporation temperature forSbCl₃ was 35° C. The growth rate was less than 0.3 Å/cycle. Attemperatures below 250° C., the growth rate was <0.1 Å/cycle. Above 300°C. the growth rate was 0.2 Å/cycle. The highest growth rate was 0.28Å/cycle at 400° C.

The film non-uniformity was about 6 to about 16%. Non-uniformity washigh (>10% 1σ) at the low deposition temperatures (150-200° C.) and atthe highest temperature 400° C. At 250-350° C. the 1σ non-uniformity was5-7%.

FIG. 4 shows film growth rate and non-uniformity at 150-400° C. Table 3presents how the addition of a H₂O pulse after or before the O₃ pulseaffects the growth rate and non-uniformity.

TABLE 3 The effect of an additional H₂O pulse after or before the O₃pulse on growth rate and film uniformity. O₃ O₃ + H₂O H₂O + O₃ Temp-Growth Growth Growth erature rate rate rate (° C.) (Å/cycle) NU %(Å/cycle) NU % (Å/cycle) NU % 400 0.28 10.4 0.38 7.4 0.38 6.4 300 0.25.5 0.37 7

The films were characterised with X-ray reflection (XRR), X-raydiffraction (XRD) and X-ray photoelectron spectroscopy (XPS) and energydispersive x-ray analysis (EDX). According to XRR, the film density was˜6-6.6 g/cm³ density increasing towards higher temperature (150 to 400°C.). The rms roughness obtained from XRR was 1.3 nm (6 nm at 150° C.),1.0 (20 nm at 300° C.) and 1.2 nm at 400° C. No clear peaks were seen inthe XRD diffractogram with a sample deposited at 400° C.; hence thefilms were assumed amorphous. According to XPS (Table 4), the oxidationstate of antimony is +3; thus the films were Sb₂O₃. Carbon and nitrogenwere detected as contamination on the surface, but after sputtering ˜5nm neither could be detected. The oxygen concentrations wereapproximated due to overlap of O1 s and Sb3d5 peaks. The decrease inO/Sb (Table 4) is believed to be due to preferential sputtering of thelow mass oxygen relative to the high mass Sb. The XPS samples weredeposited at 400° C. EDX detected no carbon or chlorine in a filmdeposited at 400° C.

Etching tests were done in 1% HF, 25% H₂SO₄, conc. HNO₃ and conc. HCl atroom temperature. The film could not be etched in any of these solutions(1-6 min etching time, with an initial film thickness of about 40 nm).

TABLE 4 XPS results. Sb₂O₃ film deposited at 400° C. The figures presentat. %. Measured before (top) and after (below) sputtering ~5 nm. C N OSb O/Sb Sample A 14.7 2 56 27.6 2 Sample A −5 nm 0 — 39 60.9 0.6

Example 3 Sb(N(CH₃)₂)₃ as the Antimony Source in a Single Wafer Reactor

Antimony oxide (SbO_(x)) thin films were deposited by Atomic layerdeposition (ALD) in a Pulsar® 2000 R&D reactor using Sb(N(CH₃)₂)₃ as theantimony source and O₃ as the oxygen source.

Films were deposited using alternate and sequential pulses ofSb(N(CH₃)₂)₃ and O₃ (in O₂) at reaction temperature of about 100-300° C.Sb(N(CH₃)₂)₃ was pulsed for 0.1-1.0 s and purged for 10 s. O₃ was pulsedfor 10 s and purged for 10 s, O₃ concentration was 250 g/m³(NTP). TheSb(N(CH₃)₂)₃ was used at room temperature (about 20° c. to about 23°C.). Carrier gas flow was 0.8 slm.

The growth rate ranged from about 0.83 to 1.92 Å/cycle. The growth ratewas about 1.44-1.92 Å/cycle at around 100° C. and from about 0.83 toabout 1.39 Å/cycle at 200° C. The film non-uniformity (with-in-wafer)varied from about 2.1% to about 7.1% (1σ). For example, a 500 cycle filmdeposited at 100° C. and with the Sb(N(CH₃)₂)₃ pulse 1 s, purge 10 s andO₃ pulse 10 s, purge 10 s, concentration 250 g/m³(NTP) had a growth rateof 1.92 Å/cycle and with-in-wafer uniformity of 2.1% (1σ). FIGS. 5 and 6present typical SbO_(x) film characteristics with Sb(N(CH₃)₂)₃+O₃.

Example 4 Sb(OEt)₃ as the Antimony Source in a Batch Reactor

Antimony oxide (SbO_(x)) thin films were deposited by atomic layerdeposition (ALD) in an commercial, production-type ASM A412™ batchreactor using Sb(OC₂H₅)₃ as the antimony source and O₃ as the oxygensource.

Films were deposited using alternate and sequential pulses of Sb(OC₂H5)₃and O₃ at a reaction temperature of about 140-220° C. Sb(OEt)₃ waspulsed for 3.0-20 s with doses of 15-40 g/hr and purged for 10-60 s. O₃was also pulsed for 3.0-20 s and purged for 10-600 s. The Sb(OC₂H₅)₃ wasused at 120° C. in liquid injection system. Carrier gas flow was variedfrom about 0.5 slm to about 0.8 slm. Both single pitch and double pitchwafer loads were used, corresponding to 100 or 50 product wafercapacity, respectively.

The growth rate ranged from about 0.38 to 0.8 Å/cycle. The growth ratewas about 0.38-0.41 Å/cycle at around 140° C. and from about 0.5 toabout 0.8 Å/cycle at 200-220° C. The film non-uniformity (with-in-wafer)varied from about 3.4% to about 13% (1σ) and wafer-to-wafer uniformityvaried from about 0.1% to about 3.9% (1σ). For example, a 200 cycle filmdeposited with double pitch loading at 200° C. and with the Sb(OEt)₃pulse 5 s, dose 25 g/h, purge 10 s and O₃ pulse 5 s, purge 600 s,concentration 350 g/m³ had a growth rate of 0.63 Å/cycle, with-in-waferuniformity of 3.4% (1σ) and wafer-to-wafer uniformity of 0.39% (1σ).

Example 5 Sb(OEt)₃ as the Antimony Source in a Single Wafer Reactor

Antimony oxide (SbO_(x)) thin films were deposited by atomic ayerdeposition (ALD) in Pulsar® 2000 R&D reactor using Sb(OC₂H₅)₃ as theantimony source and O₃ as the oxygen source.

Films were deposited using alternate and sequential pulses of Sb(OC₂H5)₃and O₃ at reaction temperature of about 200° C. Sb(OEt)₃ pulse was fixedto 0.5 s and purge to 10 s. O₃ was pulsed for 2.5-30 s and purged for 10s, O₃ concentration was 60-300 g/m³(NTP) and the O₃ flow into thereactor was 200-800 cm³/min(NTP). The Sb(OC₂H₅)₃ was heated to 40° C.Carrier gas flow was 0.8 slm.

The growth rate ranged from about 0.3 to 0.7 Å/cycle. The growth ratedepended heavily on the O₃ dosage used as shown in FIG. 7, wherediamonds present the runs where the O₃ flow in the reactor was varied,squares present the runs where the O₃ concentration was varied, andtriangles present the runs where the O₃ pulse time was varied. The filmnon-uniformity (with-in-wafer) varied from about 2.7% to about 49.5%(1σ). Higher O₃ dosage resulted in higher growth rate of the film.

Example 6 Sb(N(CH₃)₂)₃ as the antimony source in a batch reactor

Antimony oxide (SbO_(x)) thin films were deposited by atomic layerdeposition (ALD) in an commercial, production-type ASM A412™ batchreactor using Sb(N(CH₃)₂)₃ as the antimony source and O₃ as the oxygensource.

Films were deposited using alternate and sequential pulses ofSb(N(CH₃)₂)₃ and O₃ at a reaction temperature of about 200° C.Sb(N(CH₃)₂)₃ was pulsed for 5.0 s with a dose of 50 g/hr and purged for120 s. O₃ was also pulsed for 5.0 s and purged for 120 s withconcentration of 350 g/m³. Sb(N(CH₃)₂)₃ was used at 120° C. in a liquidinjection system. Carrier gas flow was 0.5 slm.

The growth rate of SbO_(x) ranged from about 1.3 to 1.4 Å/cycle. Thefilm non-uniformity (with-in-wafer) varied from about 4.5% to about 5.3%(1σ). A 4.5% film thickness non-uniformity map can be seen in FIG. 8.

What is claimed is:
 1. A method of depositing an antimony oxide thinfilm, comprising alternately and sequentially contacting a substrate ina reaction chamber with an antimony precursor and an oxygen source,wherein the antimony precursor has the formula Sb(NR₂)_(x)A_(3-x),wherein x is from 1 to 3, wherein each R is independently selected to bea linear, branched or cyclic, saturated or unsaturated, C1-C12 alkyl oralkenyl group or hydrogen if the other R is not hydrogen, and wherein Ais a ligand comprising alkylamine, halide, amine, silyl or alkyl.
 2. Themethod of claim 1, wherein the alkyl or alkenyl is substituted with atleast one substituent selected from the group consisting of halogens,amines, and silyls.
 3. The method of claim 1, wherein the antimonyprecursor comprises Sb(NMe₂)₃.
 4. The method of claim 1, wherein theantimony precursor is selected from the group consisting of Sb(NEt₂)₃,Sb(NPr₂)₃ and Sb(N^(i)Pr₂)₃.
 5. The method of claim 1, wherein theoxygen source is selected from the group consisting of water, oxygen,hydrogen peroxide, aqueous solution of hydrogen peroxide, ozone, atomicoxygen, oxides of nitrogen, peracids (—O—O—H), alcohols,oxygen-containing radicals and mixtures thereof.
 6. The method of claim1, wherein alternately and sequentially contacting the substratecomprises alternately and sequentially contacting the substrate at aprocess pressure of 0.01 mbar to 500 mbar.
 7. The method of claim 1,wherein alternately and sequentially contacting the substrate comprisesalternately and sequentially contacting the substrate at a depositiontemperature of up to 500° C.
 8. The method of claim 1, wherein thesubstrate comprises a three-dimensional structure and the antimony oxidethin film is deposited over the three-dimensional structure with a stepcoverage of greater than 80%.
 9. The method of claim 1, furthercomprising exposing the substrate to water.
 10. The method of claim 9,wherein exposing the substrate to water comprises exposing the substratesubsequent to contacting the substrate with the antimony precursor andprior to contacting the substrate with the oxygen source.
 11. A methodof depositing an antimony oxide layer on a substrate by atomic layerdeposition, comprising: contacting a surface of the substrate with anantimony precursor having the formula Sb(NR₂)_(x)A_(3-x), wherein x isfrom 1 to 3, and each R is independently selected to be linear, branchedor cyclic, saturated or unsaturated, C1-C12 alkyl or alkenyl group orhydrogen if the other R is not hydrogen, and wherein A is a ligandcomprising alkylamine, halide, amine, silyl or alkyl, such that theantimony precursor adsorbs on the substrate surface; and exposing thesubstrate to an oxygen source, wherein the oxygen source reacts with theantimony precursor on the surface of the substrate to form the antimonyoxide.
 12. The method of claim 11, wherein contacting comprisescontacting the substrate in a batch reactor.
 13. The method of claim 11,wherein contacting comprises contacting the substrate in a single-waferreactor.
 14. The method of claim 11, wherein the oxygen source comprisesozone.
 15. The method of claim 11, wherein the oxygen source is notwater.
 16. The method of claim 11, wherein exposing the substrate to theoxygen source comprises exposing the substrate to an oxygen-containinggas pulse, wherein the oxygen-containing gas pulse comprises the oxygensource and an inactive gas.
 17. The method of claim 11, wherein theoxygen source comprises at least one of oxygen and ozone, and whereinthe inactive gas comprises nitrogen or argon.
 18. The method of claim11, wherein the alkyl or alkenyl is substituted with at least onesubstituent selected from the group consisting of halogens, amines, andsilyls.
 19. The method of claim 18, wherein the antimony precursorcomprises Sb(NR₂)₃.
 20. The method of claim 19, wherein the R is alinear or branched, cyclic or linear, saturated or unsaturated, C1-C12alkyl or alkenyl group.